Hydraulic shock absorber



Original Filed April 30 Patented Oct. 2, 1934 HYDRAULIC SHOCK ABSORBER Klaas Landeweer, Utrecht, Netherlands Original application April 30, 1931, Serial No. 533,982. Divided and this application August 6,

1932, Serial No. 627,698.

January 21, 1931 4 Claims.

My invention relates to shock absorbers, and more particularly to shock absorbers for use in connection with motor vehicles, such as described in my application for patent, Serial No. 533,982, filed April 30, 1931, of which application this is a division.

The object of shock vehicles and the like is so to coact with the springs of the same that the body shall move upward and downward as little as possible when travelling over rough roads. Hydraulic shock absorbers are ordinarily so constructed that they damp more strongly the upwardly directed body movements than the downwardly directed movements, because the latter are also taken up by the springs.

Shock absorbers of absorbers for motor various types are regulated according to the weight of the vehicle or the wishes of its purchaser; their effect upon body movements is usually satisfactory but may be inadequate in special cases, for example, when curves are taken, or when the road is very uneven. Owing to centrifugal force in the first case, and to the depressions of the road in the second case, the body tends to deviate from the normal horizontal position.

The object of my present invention is a hydraulic shock absorber, whereby the downwardly directed movements of the body are more strongly braked during tilting than during the normal up and down motion.

In order that my invention may be well understood, I shall now proceed to describe the same with reference to the drawing, on which Figs. 1 and 2 show two different embodiments, both in a vertical sectional view. Fig. 3 shows the device attached to the vehicle body of a motor car.

In Fig. l, the cylinders 1 and 2 of the shock absorber are ailixed to the chassis or other suspended part of the vehicle and contain pistons 3, 4 having rods 5, 6 secured at their lower ends to one of the axles. Said cylinders are filled with a liquid, preferably oil, which can only escape through a small aperture 7 (8) in the piston when the cylinder moves upwards (or when the piston moves downwards), and which, during movement in the opposite direction, can moreover flow through a by-pass 9 (10) having a check-valve 11 (12) thereby braking differentially the movements of the pistons to the degree required. In principle, these parts may be considered to be known.

According to the invention, the by-pass 9 (10) is arranged to comprise a normally open cock 13 (14), which may be closed to a greater or lesser In the Netherlands degree or even entirely by means of an arm 15 (16) operatively connected with a rod 1'1 (18). The rod 17 carries two small discs 19, 20, between which are mounted a fixed disc 21 and a spring 22. The spring tends to press disc 19 against fixed disc 21. Corresponding members are mounted uponrod 18, to wit, two small disks 23 and 24, a fixed disk 25 and a spring 26. The pin 2'7 of a weight 28, pendulously suspended from a bar 29 hinged at 30 to the chassis, is fitted between the 6B ends of rods 17, 18. The pivot 30 of rotation of the bar 29 is disposed horizontally in the vertical central plane of the vehicle.

When the vehicle begins to tilt towards the left or to take a right-hand curve, weight 28 moves from its central position towards the left, thereby pushing rod 1'1 towards the left and partly or wholly closing cock 13. The flow of liquid through by-pass 9 is in consequence throttled and the downward movement of cylinder 1 (mounted on ll the left-hand side of the chassis) is'braked beyond the normal degree.

The same action takes place on the right-hand side, when the vehicle body tilts in that direction or when a left-hand curve is taken.

In Fig. 2, the pivot 31 is situated below the weight 32, whose rod coacts with two fixed electric contacts 33, 34, each of which is connected by an electro-magnet 35 (36) to one pole of a battery 3'7, the other pole of battery 3'7 being connected to the pivot 31. The weight 32 is normally retained in its central position by a spring 38, when the rod is kept clear of contacts 33, 34. As the weight swings towards the left or towards the right, the rod engages contact 33 or 34, whereby the circuit of electromagnet 35 (36) is closed, the armature 39 (40) fixed to rod 17 (18) is attracted and, consequently, cook 13, (14) iswholly or partly closed.

What I claim is: V

1. A hydraulic shock absorber for motor and other vehicles comprising two chambers designed to contain the liquid for controlling the movements of the chassis relative to a vehicle axle, one wall of each of said chambers being formed by a piston slidingly mounted within a cylinder and adapted to be connected to the vehicle axle so as to alternately increase and diminish the volume of said chambers upon the chassis moving in vertical direction relative to the vehicle axle, the passage of liquid to and from either of said chambers being controlled by throttling, and one-way valve means so that under normal conditions the resistance caused by the shock absorber against upward movement of the chassis 110 exceeds the resistance against its downward movement, an adiustable throttling means disposed in a duct leading from the chamber decreasing in volume during the downward move ment of the chassis relative to the vehicle axles, and a gravity controlled member adapted for swinging motion about a substantially horizontal axis disposed substantially in the vertical central plane of the vehicle, said gravity controlled memher being operatively coupled with the said throttling means.

2. A hydraulic shock absorber for motor and other vehicles as claimed in claim 1, wherein said gravity controlled member has its centre of gravity disposed above its swinging axis and is connected to a spring tending to keep it in its central position.

3. A hydraulic shock absorber for motor and other vehicles as claimed in claim 1, wherein said gravity controlled member has its centre of gravity disposed above its swinging axis and is connected to a spring tending to keep it in its central position, electric contacts disposed on either side of said member, electromagnets the circuits of which are adapted to be closed and opened by said contacts, and means whereby said magnets are adapted, on energzation to operate the said throttling means.

4. In a hydraulic shock absorber for a vehicle, a substantially vertical cylinder secured to and mounted on one side of the vehicle body, a second substantially vertical cylinder secured to and mounted on the other side of the vehicle body, pistons working in said cylinder, rods secured to said pistons and both engaging one axle of the vehicle, permanently open passages through which the cylinder spaces on either side of each piston are in communication, by-passes connecting both ends of each cylinder, check valves disposed in said by-passes so as to prevent flow of liquid from the bottom of the cylinders to the tops thereof, throttling valves in said by-passes, a weighted member adapted for swinging movement about a horizontal axis disposed substantially in the central vertical plane of the vehicle, and means for transmitting movements of said weighted member about its axis to both said throttling valves.

KLAAS LANDEWEER. 

